ABT AS5-R: Modified Audi S5 with 510HP set for Geneva Debut   .fullpost{display:inline;} The Audi S5-based AS5-R from ABT Sportsline will be making its worldwide debut at next month's Geneva Show. ABT's tuning proposal for the most powerful variant of the A5 coupe includes an updated version of the current S5's 344HP 4.2-liter V8 engine that has been modified